Conventionally, at machining factories, a plurality of pieces of production equipment is placed in line to perform multiple steps required to produce products, providing a production line that produces products in a flow process. Further, in fields of production management, it is always required to improve productivity in the production lines and to promote energy saving, such as a reduction in power consumption and the like.
Operation information (i.e., operation-state, power consumption, and the like) of each piece of production equipment in a production line is useful in improving productivity of the production line and saving energy.
Thus, for example, a technology disclosed in Patent Literature 1 measures power consumption for each piece of production equipment, and stores an operation-state of the piece of production equipment in a memory. The operation-state is determined based on power consumption of the piece of production equipment and power consumption of other pieces of production equipment corresponding to the piece of production equipment.
Patent Literature 2 discloses a technology that measures in real time an operation signal that specifies an operation-state of production equipment, determines the operation-state based on characteristics of the measured signal, and stores the operation-state as operation information.
In addition, in order to improve productivity, it is necessary to perform maintenance on production equipment at proper timing. Thus, for example, a power system monitoring system described in Patent Literature 3 changes timing of maintenance based on whether or not electric current flowing through the power system equipment exceeds reference electric current and whether or not a shut-off operation has been performed. In addition, a maintenance and inspection time informing device described in Patent Literature 4 measures mileage of vehicles, such as an automobile. When the mileage reaches a predetermined distance, the maintenance and inspection time informing device informs a driver of an arrival of maintenance time by displaying a warning or the like. Moreover, a machine tool power monitoring device described in Patent Literature 5 issues an alert based on the amount of average power and the amount of fluctuation in instantaneous power of the machine tool in order to prompt for maintenance and repair.